A conventional DC motor control device 100 is illustrated in FIG. 1 for controlling a DC motor 400, and includes a diode 101, a switch 102 and a capacitor 103. The conventional DC motor control device 100 lacks a reverse installation protection, and thus, the diode 101 and the switch 102 may be damaged by a large current flowing therethrough when a user mistakenly installs a DC power source 200 reversely on the conventional DC control device 100. In addition, relatively large variation in amplitude of a current provided by the conventional DC motor control device 100 to the DC motor 400 may cause high electromagnetic interference (EMI) and large current ripple as well, resulting in imprecise measurement of locked-rotor current (also called stall current), and thereby damaging the DC motor 400.